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FOSSIL LACERTIAN REPTILES 



miniature, the teeth of that great carnivorous reptile. To the question whether 

 these Purbeck fossils might not be of a foetus or young of Megalosaurus, the 

 answer is, that the lower jaw of the Nuthetes differs from that of Megalo- 

 saurus in not having the inner alveolar wall developed in the same degree, and in 

 not exhibiting any rudiments of alveolar divisions.* The inner wall is not pro- 

 duced in a greater degree than in the modern Varani. The largest teeth measure 

 two lines in diameter at the base of the crown, which is more or less excavated on 

 the inner side by the pressure of the matrix of a successional tooth. 



The length of the largest fragment of the mandible was one inch and a half ; 

 the depth of the outer wall was six lines, that of the inner wall was from three to 

 four lines. The exterior surface of the bone is smooth and polished, but shows 

 under the pocket lens very fine longitudinal linear markings ; it is perforated by 

 a series of nervo-vascular foramina along the alveolar wall, and is traversed near 

 the lower margin by a line answering to the suture dividing the dentary from the 

 angular piece in the jaw of Varanus. 



The fossils give evidence of a carnivorous or insectivorous lizard of the size of 

 Varanus crocodilinus, or great land monitor of India. The specific name 

 relates to the adaptations of the teeth for piercing, cutting, and lacerating the 

 prey. 



Of the vertebral characters I have not, as yet, received satisfactory evidence. 

 Nuthetes destructor is referred solely on mandibular and dental characters to 

 the " pleurodent section" of the order Lacertilia. But, in the same division of 

 the Purbeck strata, viz., from the "Feather Quarry," containing Cyclas and 

 Planorbis, have been found long bones of a small Saurian and dermal scutes, 

 agreeing, in regard to proportional size, with the jaw and teeth of Nuthetes. The 

 bones present the characters of tibia and fibula, and are longer in proportion to 

 their breadth than in any known recent form of Crocodilian ; they are associated 

 in the same slab with the scutes, which are subquadrate in form, about eight lines 

 in one diameter and six lines in the opposite ; smooth on the inside, impressed by 

 minute, circular pits on the outside, and presenting more the character of the bony, 

 dermal scutes of Crocodilia than of those of any known species of Lacertilia so 

 defended. Additional evidence is needed to determine the relations of these 

 small, pitted, dermal scutes to the bones and teeth of Nuthetes. 



* ' Monograph on Megalosaurus, vol. for 1856, p. 21. 



